Class II bacteriocins of Streptococcus pyogenes

被称为化脓性链球菌的细菌经常会引起一系列人类感染，然而这种生物体的“自然”栖息地是咽喉或皮肤上的非疾病状态。这表明这种细菌擅长避免被免疫系统识别，但也必须能够在这个有限的生物生态位内与其他内源性微生物竞争。我们的NSERC资助的研究项目以前发现，化脓性链球菌可以产生小分子（称为细菌素），可以杀死其他细菌。奇怪的是，当细菌在实验室条件下生长时，这些分子并没有产生，但当细菌用于喉咙定植的小鼠模型时，它们被“打开”。该应用将发现化脓性链球菌用于控制这些细菌素生产的机制，并将揭示当不同细菌素混合在一起时会发生什么，并假设这将导致更广泛的竞争细菌被杀死。该应用程序还将尝试了解化脓性链球菌如何保护其自身细菌素不被杀死的机制，这一概念称为细菌素免疫。这项工作将有助于了解化脓性链球菌的进化和生态。

The bacterium known as Streptococcus pyogenes can frequently cause a range of human infections, however the 'natural' habitat for this organism is a carriage, non-disease state in the throat or on the skin. This suggests that this bacterium is adept in avoiding recognition by the immune system, but must also be able to compete with other endogenous microorganisms within this limited biological niche. Our NSERC-funded research program had previously discovered that Streptococcus pyogenes can produce small molecules (called bacteriocins) that can kill other bacteria. The molecules were curiously not produced when the bacteria were grown under laboratory conditions, but they were 'turned on' when the bacteria was used in a mouse model of throat colonization. This application will discover the mechanisms that Streptococcus pyogenes uses to control the production of these bacteriocins and will uncover what happens when different bacteriocins are mixed together with the hypothesis that this will result in killing of a broader range of competitor bacteria. The application will also try to understand the mechanisms by how Streptococcus pyogenes is protected from killing by it's own bacteriocins, a concept known as bacteriocin immunity. This work should help to understand the evolution and ecology of Streptococcus pyogenes.